SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eceb0addbd7f329cc01205054633441c3030645f9ccdbc94d2469d15832644d' 
  AND token = 'Jf61Vh1wTKTu1w8gn4KHb/ioUGC1Lwik8bHHslxIv9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}